The above mentioned supports in the form of pallets or the freight container bottoms are equipped with interlocking elements or latching devices for securing the supports to a floor in the aircraft. Where the floor is a loading floor, it is normally equipped with transport rollers or ball elements forming a floor surface on which freight container bottoms can be moved.
Various freight latching system for securing pallets and containers to a floor in an aircraft are known in the art. Such systems include latching elements for securing the pallets or containers to the floor grid structure of the aircraft. Efforts have been made to reduce the weight of such systems and to minimize loss in vertical loading height above the respective floor. For example, conventional pallets carrying passenger seats installed on a cabin floor in an aircraft reduce the initially available cabin height by about three inches which in turn reduces the passenger comfort.
Swiss Patent Publication CH 349,493 discloses a system for transporting and latching freight containers or freight pallets to the cross-beams of a floor grid structure in an aircraft. Such a system requires that the bottoms of the containers or the pallets are equipped with interlatching elements and the floor structure must be equipped with transport rollers for moving the containers or pallets into a latching position. In the floor structure U-sectional stringers are secured to cross-joists to form a floor grid. Latching elements are secured to the pallets and containers and to the floor grid structure at predetermined spacings from one another. These spacings are determined by the spacings between the latching elements secured to the containers and pallets. Additionally, each pallet and container must be provided with its own rollers or roller balls for rolling along the floor. The longitudinal stringers are so constructed that their inner upwardly facing sides provide a surface on which the rollers or balls of the pallets or freight containers can roll along into the latching position. The need for each container and each pallet to be equipped with its own transport rollers secured to the underside of the platform or container bottom is a disadvantage because these rollers or ball rollers take up vertical space.
U.S. Pat. No. 2,625,118 discloses an apparatus for securing freight containers to the cross-joists of the aircraft floor grid structure. In the known system rail elements are secured to the cross-joists and these rail elements cooperate with latching elements and with the transport rollers of the freight containers. These rail sections are so positioned that they project out of approximately U-shaped grooves above the floor level in the aircraft so that the transport rollers of the freight containers must travel at a substantial spacing between the container downwardly facing bottom surface and the top floor level. Such a system wastes vertical loading space and therefore leaves room for improvement in reducing the vertical height that is required for moving pallets and/or freight containers along the floor.